Dennis wrote: > My assumption is that a polarizer is not perfect and reduces > but does not completely eliminate unpolarized light light. Nicolas wrote: > Your guess is right. I use a linear polariser too and it works > quite ok in AF with my fixed focal lenses and my F601 and F801s. > I can guarantee that AF does not work with a front-rotating zoom. Hello! I'm not an expert at this, but from what I remember from my physics lectures, light is polarized by glass and similar surfaces too, if the angle is around 56 degrees. And since the AF module is at the bottom of the mirror box, light has to be reflected by a little mirror behind the mirror. This would be the second time that the same light beam is polarized (after the polarizer itself), and with the right (wrong) angle, it could be completely supressed. Of course, if you say it worked, then you must have been using a certain angle that allowed some light to reach the AF module. With the light meter it's a little different, although light also has to be reflected by a mirror and could be polarized. The difference is that the whole area of the mirror is used, not just its central part, and therefore different light beams form different angles with it, so there's enough information transmitted to the light meter. I hope this has helped you. Greetings, Friedrich
